** 2013 Biology HL Before/After **

EoghanIRL

yoppo wrote: »

I always thought it was crap. There should be more human biology in biology... less plants!

Do you know the question: "Suggest an advantage to the cell of having a selectively permeable membrane"

What did you write? I couldn't think of anything!!

All I said was in the nuclear membrane RNA can enter and leave but DNA cant. I know it's right but I'm not sure if they wanted a benefit of a cell membrane.

Hmm.. I would have said it enables the cell to control what bio molecules enter and leave the cell thus ensuring an essential balance .

thegreatescape

EoghanIRL wrote: »

Hmm.. I would have said it enables the cell to control what bio molecules enter and leave the cell thus ensuring an essential balance .

I said that

Inspector Coptoor

yoppo wrote: »

I always thought it was crap. There should be more human biology in biology... less plants!

Do you know the question: "Suggest an advantage to the cell of having a selectively permeable membrane"

What did you write? I couldn't think of anything!!

All I said was in the nuclear membrane RNA can enter and leave but DNA cant. I know it's right but I'm not sure if they wanted a benefit of a cell membrane.

An advantage would be to allow nutrients into the cell while keeping foreign bodies out.

The nuclear membrane isn't really selectively permeable - it has pores to allow RNA in and out

yoppo wrote: »

I said products...! I don't know if it's that simple though.

Product(s) is the answer

Slow Show wrote: »

Let's say for the question about the two biological similarities between the Nitrogen Cycle and Carbon cycle, now I had about four down but some of those probably weren't acceptable as answers, some were. How does it work out there?

Section C question
Your first two answers would be taken, no more.

shanelad95

for the advantages of a selectively permeable membrane, could you say. advantage is some molecules such as minerals can pass into the cell where as harmful molecules are prevented from passing through?

Inspector Coptoor

conan955 wrote: »

for the advantages of a selectively permeable membrane, could you say. advantage is some molecules such as minerals can pass into the cell where as harmful molecules are prevented from passing through?

Pretty much a perfect answer

shanelad95

is wind speed an abiotic factor by any chance? haha

Inspector Coptoor

Wind maybe, dunno about the speed

shanelad95

like i used the stuff from geography, ie To measure wind speed we used an annemometer and took readings from an area of high altitude..

Inspector Coptoor

If you're habitat study was in a defined grassland or shoreline, how would you take measurements from high altitude?

One of the answers they were looking for was probably:
Light intensity

200c200c

Inspector Coptoor wrote: »

If you're habitat study was in a defined grassland or shoreline, how would you take measurements from high altitude?

One of the answers they were looking for was probably:
Light intensity

I said rainfall would that count ?

EoghanIRL

conan955 wrote: »

for the advantages of a selectively permeable membrane, could you say. advantage is some molecules such as minerals can pass into the cell where as harmful molecules are prevented from passing through?

Is say that's full marks to be honest .

shanelad95

Inspector Coptoor wrote: »

If you're habitat study was in a defined grassland or shoreline, how would you take measurements from high altitude?

One of the answers they were looking for was probably:
Light intensity

funny thing is, both my biology investigation and geog were on the same beach.. haha so like they cant really prove we didnt take readings can they ?

user.name

conan955 wrote: »

like i used the stuff from geography, ie To measure wind speed we used an annemometer and took readings from an area of high altitude..

I got the measurement thing right, thats from jc geography :pac:

internet_user

conan955 wrote: »

is wind speed an abiotic factor by any chance? haha

for this i said light intensiy and remember from JC geography the stevensons screen? is that right?

kevin12345

internet_user wrote: »

for this i said light intensiy and remember from JC geography the stevensons screen? is that right?

Light intensity yes, but I think you use a light meter? A luxometer. Never seen stevensons screen in the marking scheme. Wind speed is an abiotic factor, you use and anaemeter (sp?) to measure it.

amicus

RML wrote: »

I had 3 pairs..

its 6..you put 3 pairs of chromatids

HugsiePie

Inspector Coptoor wrote: »

Pretty much a perfect answer

How about no need for a contract vacuole for a semipermeable membrane........ I went blank

DavidDaly

I said energy from food as a guess, would they accept it? I feel like a fool because that question nearly blanked me

weirdspider

Inspector Coptoor wrote: »

If you're habitat study was in a defined grassland or shoreline, how would you take measurements from high altitude?

One of the answers they were looking for was probably:
Light intensity

How about atmospheric pressure using a barometer?

Slow Show

Y'know for the ecology experiment? For the habitat I said 'grassland', and then for the plant adaptation I said an oak tree I think. Now I probably should've used a different plant than one which would automatically be associated with a woodland habitat but things are different in the exam. :L Like I mean I genuinely did go to a grassland habitat and there definitely were a few trees there, so it's not like I'm lying or trying to defy the rules of nature.

Is that OK...? Am I overthinking this?

aimzLc2

Slow Show wrote: »

Y'know for the ecology experiment? For the habitat I said 'grassland', and then for the plant adaptation I said an oak tree I think. Now I probably should've used a different plant than one which would automatically be associated with a woodland habitat but things are different in the exam. :L Like I mean I genuinely did go to a grassland habitat and there definitely were a few trees there, so it's not like I'm lying or trying to defy the rules of nature.

Is that OK...? Am I overthinking this?

I don't know if you can find an oak tree in a grassland , i did a woodland but they do stress that your plant/animal, anything has to match your ecosystem , if there are no oak trees in a grassland ecosystem you won't get marks

amicus

aimzLc2 wrote: »

I don't know if you can find an oak tree in a grassland , i did a woodland but they do stress that your plant/animal, anything has to match your ecosystem , if there are no oak trees in a grassland ecosystem you won't get marks

theres an oak tree in my back garden

Slow Show

Look there's an oak tree here



I'm not overly bothered, I did all the experiment q's but I think I got 27/30 in all of them if they don't accept oak tree. Not the worst thing ever but these marks here and there don't help when you feel as borderline between A1/A2 as I do.

aimzLc2

Slow Show wrote: »

Look there's an oak tree here



I'm not overly bothered, I did all the experiment q's but I think I got 27/30 in all of them if they don't accept oak tree. Not the worst thing ever but these marks here and there don't help when you feel as borderline between A1/A2 as I do.

i'm sure oak tree is fine :P

amicus

Slow Show wrote: »

Look there's an oak tree here



I'm not overly bothered, I did all the experiment q's but I think I got 27/30 in all of them if they don't accept oak tree. Not the worst thing ever but these marks here and there don't help when you feel as borderline between A1/A2 as I do.

I think I mite have gotten full marks in section c..i did all the questions. I did well in experiments..the denaturation graph is off putting..my guess is they'll give the marks for a sensible attempt.as for the short question this was my downfall . could of lost 10 marks or so who knows

Inspector Coptoor

HugsiePie wrote: »

How about no need for a contract vacuole for a semipermeable membrane........ I went blank

no, that wont be acceptable I'm afraid.
amoeba has a cell membrane and has vacuoles

weirdspider

Inspector Coptoor wrote: »

no, that wont be acceptable I'm afraid.
amoeba has a cell membrane and has vacuoles

If you said an abiotic factor was atmospheric pressure measured using a barometer?

roberth

Hi lads, just asking ye're opinion on a couple of the questions. Thought the questions were a bit unclear at times.

For 14 (c), when asked for a carbon compound I said glucose? and the immobilizing beads part I said calcium alginate? would they be right do ye think? I had sodium alginate written down but when I thought back to the experiment itself I remembered the beads were formed when you added the sodium alginate - yeast mixture to the calcium chloride, therefore calcium alginate beads, Very confused so I was.

And for the endospore question I stupidly forgot to say that about the DNA being enclosed by the spore, I just said it formed in the parent cell and then a protective protein wall formed around it. You see, in home ec we learned about endospores as well and I mixed up the two definitions and left out that important bit. D'ye think I'd lose a couple marks or is that sufficient?

Very annoyed with the paper, I got an A1 in the mocks and I don't feel it went as well at all in the real thing. Ah well, not the end of the world. I'm fair ragin' at the SEC this year though, it's like they decided to let trainees or something write the papers this year. Or they took this year handy and give us odd and unclear questions. I know I'm not alone with this thought. What do ye think?

Inspector Coptoor

weirdspider wrote: »

If you said an abiotic factor was atmospheric pressure measured using a barometer?

this is getting at weather/climate so should be ok.

If you did it in your investigation and its on the syllabus, its acceptable and will be in the marking scheme.

However, I have to say, I've NEVER taken this measurement on an ecology field trip myself.

roberth

roberth wrote: »

Hi lads, just asking ye're opinion on a couple of the questions. Thought the questions were a bit unclear at times.

For 14 (c), when asked for a carbon compound I said glucose? and the immobilizing beads part I said calcium alginate? would they be right do ye think? I had sodium alginate written down but when I thought back to the experiment itself I remembered the beads were formed when you added the sodium alginate - yeast mixture to the calcium chloride, therefore calcium alginate beads, Very confused so I was.

And for the endospore question I stupidly forgot to say that about the DNA being enclosed by the spore, I just said it formed in the parent cell and then a protective protein wall formed around it. You see, in home ec we learned about endospores as well and I mixed up the two definitions and left out that important bit. D'ye think I'd lose a couple marks or is that sufficient?

Very annoyed with the paper, I got an A1 in the mocks and I don't feel it went as well at all in the real thing. Ah well, not the end of the world. I'm fair ragin' at the SEC this year though, it's like they decided to let trainees or something write the papers this year. Or they took this year handy and give us odd and unclear questions. I know I'm not alone with this thought. What do ye think?

I wasn't sure of what they wanted either so I wrote both down with a note saying I didn't understand what the question was looking for (they probably won't like that)
As for the selective permeable membrane, I thought of the answer everyone is saying but thought "sure we get sick all the time, it doesn't keep harmful stuff out" and wrote "so not too much osmosis occurs which would burst the cell"
Talk about blonde moment!